//成绩等级，苏小红教材习题5.9改写，使用switch结构
#include <stdio.h>
int main()
{
    int score;
    char grade;
    scanf("%d",&score);
    switch(score/10)
    {
    case 10:
    case 9:
        grade = 'A';
        break;
    case 8:
        grade = 'B';
        break;
    case 7:
        grade = 'C';
        break;
    case 6:
        grade = 'D';
        break;
    default:
        grade = 'E';
    }
    printf("grade = %c\n",grade);
    return 0;
}